Comparative Analysis on Influencing Factors of Alignment Monitoring Between Continuous Rigid-frame Bridge and Continuous Girder Bridge

Abstract

In this paper, finite-element models are created for a continuous rigid-frame (CRF) system and a continuous girder (CG) system with the same superstructure. Next, two indices were selected to measure the difficulty of alignment monitoring, namely, the cumulative displacement in cantilevering and the difference between the two sides of the closure gap (the cross-gap difference) in cumulative displacement. After that, the two models were utilized to analyze how design parameters, pre-tensioning sequence and closure sequence affect the alignment monitoring difficulty of the two types of bridges. The analysis shows that the CRF bridge was less affected by prestress force and closure sequence than the CG bridge. This means the pretensioning sequence has greater impacts on the cumulative displacement of the CRF bridge than the CG bridge. The reasons for the impacts were further analyzed, and the closure sequence was rationalized. The research findings shed important new light on the alignment monitoring of CRF bridges.